Heat a little oil in a frying pan. Cook pork on both sides for about 5 minutes and remove any excess oil with a paper towel once fully cooked through.
Fill a saucepan with stock. Add the cooked pork cubes with the onion, carrot, celery, mirin, soy sauce, half the ginger and spring onion.
Place over a high heat until the water boils, then decrease to a medium heat and allow it to simmer for approximately 1 1/2 to two hours or until pork is tender.
Add the bok choy, gai lan, the eggs, the remaining spring onions and ginger.
